This Practice Advisory represents the current information available regarding Zika virus. When new information becomes available, the entire Practice Advisory is reviewed and individual sections are updated as needed and dated accordingly.

The virus spreads to humans primarily through infected Aedes species mosquitoes (Ae. aegypti and Ae. albopictus), from mother to her fetus during pregnancy, and through sexual contact, although Zika virus transmission may also occur through blood transfusion and through laboratory exposure. Zika virus disease is defined as having at least one of the following signs or symptoms: acute onset of fever, rash, arthralgia, conjunctivitis and laboratory confirmation of Zika virus infection. It appears that only about one in five infected individuals will exhibit these symptoms and most of these will have mild symptoms. Once a person is infected, the incubation period for the virus is approximately 3–14 days. This time frame is suggested based on limited experience from Zika virus cases as well as extrapolation from data on other flaviviruses. Possible Zika virus exposure is defined as travel to or residence in an area of active Zika virus transmission (http://www.cdc.gov/zika/geo/index.html), or sex without a condom with a partner who traveled to or lived in an area of active transmission. Anyone who lives or travels to an area where Zika virus is found and has not already been infected with Zika virus is at risk of contracting Zika virus. Once a person has been infected, he or she is likely to be protected from future infections, although this is based on limited data and experience from other flaviviruses and has not been confirmed.

It is not known if pregnant women are at greater risk of Zika virus transmission than non-pregnant individuals. However, there is demonstrated causation between Zika virus infection during pregnancy and adverse pregnancy outcomes such as pregnancy loss, microcephaly, and other brain and eye abnormalities. Transmission of Zika virus to the fetus has been documented in all trimesters; Zika virus RNA has been detected in fetal tissue from early missed abortions, amniotic fluid, term neonates, and the placenta. However, much is not yet known about Zika virus in pregnancy. Uncertainties include the incidence of Zika virus infection among pregnant women in areas of Zika virus transmission, the rate of vertical transmission, and the rate with which infected fetuses manifest complications such as microcephaly or demise. However, one study utilizing modeling based on the Zika virus outbreak in French Polynesia (Cauchemez 2016) suggested microcephaly would occur in 1%-13% of babies born to mothers infected in the first trimester, and a recent cohort study from Brazil (Brasil 2016) found abnormal outcomes including stillbirth, growth restriction, and microcephaly and other sonographic abnormalities in 29% of fetuses of Zika virus-infected mothers in all trimesters.

Currently, real-time reverse transcription polymerase chain reaction (rRT-PCR), immunoglobulin M (IgM), and plaque reduction neutralization (PRNT) tests are available to detect Zika virus infection, although each test has limitations (see Testing below). Currently, there is no reliable IgG test available in the U.S. to test for acquired immunity to Zika virus. There is no vaccine or treatment for this infection.

Travel Restrictions

(Updated: December 2, 2016)

Pregnant women should not travel to areas where Zika outbreaks are ongoing, including some areas within the continental U.S. Areas that pregnant women should avoid or for which pregnant women should consult with their obstetrician-gynecologist before traveling include:*

Pregnant women and their partners who must travel to one of these areas should strictly follow steps to prevent mosquito bites during the trip and decrease the risk for sexual transmission (see Prevention).

Women considering pregnancy should discuss with their obstetric providers the advisability of travel. See the CDC and PAHO web sites for updated lists of affected countries and states. At this time, travel warnings have been released for countries where local mosquito transmission of Zika Virus has been reported.

*Areas of local transmission within the U.S. will likely change frequently. Fellows should check this list periodically for revisions and updates.

†The date to begin assessment, testing, and management of pregnant women and their partners in these areas varies. Providers should check the CDC links provided here for exact dates.

Prevention

(Updated: October 18, 2016)

Avoiding exposure is best:

When traveling to areas where Zika virus has been reported, women should take all precautions to avoid mosquito bites including the use of EPA-approved bug spray with DEET, covering exposed skin, staying in air-conditioned or screened-in areas, and treating clothing with permethrin.

Providers should specifically communicate to pregnant women that when used as directed on the product label, EPA-registered insect repellents, particularly those with DEET and permethrin, can be used safely during pregnancy.

These protective measures should be followed both day and night as the Aedes aegypti mosquito (which carries Zika virus) bites primarily during the day as well as at dusk and dawn. Reapplication of insect repellant should be practiced as directed on the product label.

Consistently and correctly using condoms during sex or abstaining from sex for the duration of the pregnancy is recommended if you have a sex partner that has traveled to or lives in an area with active Zika virus transmission.

Reproductive Counseling

(Updated: October 18, 2016)

Guidance related to reproductive counseling is outlined below. Please see Testing for guidance on testing of pregnant and non-pregnant women.

Obstetrician–gynecologists and other health care providers should discuss pregnancy intentions and reproductive options with all women of reproductive age for shared decision making. In the context of the ongoing Zika virus outbreak, preconception care should include a discussion of the signs and symptoms and the potential risks of Zika virus infection. Health care providers should discuss their patients’ reproductive life plans in the context of potential Zika virus exposure. View CDC's guide for preconception counseling in context of Zika.

Sexual Transmission:

Sexual transmission of Zika virus has been reported, including male-to-female and female-to-male transmission, when the sexual contact did not include a barrier to protect against infection, but the frequency and efficiency of this route of infection is uncertain. Barriers against infection include male or female condoms for vaginal sex, male condoms for oral sex, and male condoms cut to create a flat barrier or dental dams for oral sex.

Most reported sexual transmissions have been from persons with symptomatic Zika virus infections, although sexual transmission can occur from a man with asymptomatic Zika virus infection. Among reported cases of sexually transmitted Zika virus infection, the longest reported period between symptom onset and sexual contact that might have transmitted Zika virus was 32–41 days.

Data on the detection of Zika virus RNA in semen can inform estimates of the time periods during which sexual transmission might occur. However, detection of Zika virus RNA in semen may not indicate the presence of infectious virus and thus the potential for sexual transmission. Many reports indicate that concentrations of detectable Zika virus RNA in semen decrease after infection, with the longest reported detection at 188 days after symptom onset. Culture is considered the gold standard for demonstrating the presence of replicative and thus infectious virus and Zika virus cultured from semen has been documented up to 69 days after symptom onset.

Additional studies are needed to characterize the risk of sexual transmission of Zika virus; as more information becomes available, recommendations will be updated.

Given the potential risks of maternal Zika virus infection, pregnant women with sex partners (male or female) who live in or have traveled to an area with active Zika virus transmission should consistently and correctly use condoms or other barriers against infection during sex (vaginal, anal, or oral) or abstain from sex for the duration of the pregnancy.

Men and women who are not pregnant and want to reduce the risk for sexual transmission of Zika virus should use condoms or other barriers against infection consistently and correctly during sex (vaginal, anal, or oral) or abstain from sex when one sex partner has traveled to or lives in an area with active Zika virus transmission.

The recommended duration of consistent use of a condom or other barrier against infection or abstinence from sex for couples who have possible exposure to Zika virus depends on whether the partner is male or female:

Couples in which a partner has possible exposure to Zika virus through recent travel or sex without a condom with a partner infected with Zika virus.

Men with possible Zika virus exposure who are considering pregnancy with their partner, regardless of symptom status, should wait at least 6 months after symptom onset (if symptomatic) or last possible Zika virus exposure (if asymptomatic) to attempt pregnancy with their partner.

Women who have had possible Zika virus exposure, regardless of symptom status, through travel or sexual contact and do not have ongoing risks of exposure should wait at least 8 weeks from symptom onset (if symptomatic) or last possible exposure (if asymptomatic) to attempt pregnancy.

Given that limited data are available, some couples in whom a partner had possible Zika virus exposure might choose to wait longer or shorter than the recommended period to attempt pregnancy, depending on individual circumstances (e.g., age, fertility, details of possible exposure) and risk tolerance.

Couples who are not pregnant and are not planning on becoming pregnant should also be counseled to correctly and consistently use condoms in addition to their chosen method of birth control for vaginal, anal, and oral sex or abstain from sex during this time period if they are concerned about the possibility of transmitting Zika virus to their sex partners.

Couples living in or frequently traveling to an area with active Zika virus transmission:

If you or your partner are not pregnant and are not planning a pregnancy, and reside in an area with active Zika virus transmission, consider using condoms or other barriers against infection or abstaining from sex while active mosquito-borne transmission persists. (See CDC: Protect yourself during sex.)

Women and men who reside in or frequently travel to areas with active Zika virus transmission and who experience symptoms of Zika virus disease should be tested for Zika virus infection (39).

Men with results that indicate recent Zika virus or unspecified flavivirus infection should wait at least 6 months from symptom onset to attempt pregnancy; women with results that indicate recent Zika virus or unspecified flavivirus infection should wait at least 8 weeks from symptom onset to attempt pregnancy.

Given that limited data are available, some couples in whom a partner had possible Zika virus exposure might choose to wait longer or shorter than the recommended period to be pregnant, depending on individual circumstances (e.g., age, fertility, details of possible exposure) and risk tolerance.

These recommendations are based on expert opinion, data from other flaviviruses, the limited available data on Zika virus, and knowledge about risks for other viral infections in the periconceptional period. For men, estimates are based on evidence that the virus may persist in semen for longer periods after exposure and infection.

Patients should be counseled that testing of specimens for risk of sexual transmission is not currently recommended for asymptomatic individuals because the performance of the test is not known in asymptomatic individuals (See Testing).

Women Avoiding Pregnancy:

For women who do not want to become pregnant, obstetrician–gynecologists and other health care providers should discuss strategies to prevent unintended pregnancy and provide counseling on family planning and the use of contraceptive methods. Safety, effectiveness, availability, and acceptability should be considered when selecting a contraceptive method(s).

The risk of adverse pregnancy and birth outcomes associated with Zika disease during pregnancy highlights the need to ensure that effective contraception is readily available for women and couples who live in or have recently traveled to areas with local Zika virus transmission and who do not desire pregnancy.

Women Who Desire Pregnancy:

Both women who are diagnosed with Zika virus disease and asymptomatic women with possible exposure to Zika virus should wait at least 8 weeks from symptom onset or exposure to attempt pregnancy. Their male partners with possible Zika virus exposure, regardless of symptom status, should wait to attempt pregnancy until at least 6 months after symptom onset (if symptomatic) or last possible Zika virus exposure (if asymptomatic).This advice means that those living in areas with ongoing transmission of Zika virus may decide to delay pregnancy. Those who are not planning such delay should talk with their health care providers. Obstetrician-gynecologists and other health care providers should counsel patients on the risks of Zika virus as part of their pregnancy planning and counseling. This should include counseling about the potential consequences to the fetus associated with Zika virus infection during pregnancy, such as microcephaly and other serious brain abnormalities. Health care providers should stress the use of mosquito prevention strategies while attempting pregnancy and during pregnancy.

Suggested timeframe to wait before trying to get pregnant

Possible exposure via recent travel or sex without a condom
with a partner infected with Zika

No instances of Zika virus transmission during fertility treatment have been documented, but transmission through gametes or embryos is theoretically possible. Recommendations for sexually intimate couples with Zika virus infection or possible Zika virus exposure undergoing fertility treatment with their own gametes and embryos should follow the testing and timing recommendations as described above; recommendations might need to be adjusted depending on individual circumstances. The Food and Drug Administration has issued guidance to reduce the risk of Zika virus transmission by donated human cells, tissues, and cellular and tissue-based products, including reproductive tissues.

Testing

(Updated: October 18, 2016)

All pregnant women in the U.S. and U.S. territories should be assessed for possible Zika virus exposure at each prenatal care visit. Each prenatal evaluation should include an assessment of signs and symptoms of Zika virus disease (one or more of the following signs or symptoms: acute onset of fever, rash, arthralgia, conjunctivitis), travel history, and risk of sexual exposure from a partner with a travel history to an endemic region to determine whether Zika virus testing is indicated. Sexual exposure includes vaginal, anal, or oral sex, and the sharing of sex toys without a barrier method. Pregnant women who have potentially been exposed to Zika virus (i.e., via travel or sexual contact) should be tested according to Figure 1, regardless of whether or not they also present with one or more of the Zika signs or symptoms. Testing for asymptomatic, non-pregnant sexual partners (with or without potential Zika exposure) of pregnant women is not currently supported by the CDC guidelines.

Routine Zika virus testing is not currently recommended for women or men with possible Zika virus exposure without clinical illness who are attempting pregnancy. For men, this advice in part reflects uncertainty about whether molecular or serologic testing reflects the presence or absence of Zika virus in semen. The ability to culture for Zika virus is not widely available and sending semen for Zika virus culture is not generally recommended. Additional studies are needed to determine if semen culture can reliably detect presence of infectious virus in semen.

Testing of specimens to assess risk for sexual transmission is currently not recommended. However, Zika virus testing of serum and urine is recommended for persons who have had possible sexual exposure to Zika virus and who develop signs or symptoms consistent with Zika virus disease (http://www.cdc.gov/zika/laboratories/lab-guidance.html).

Providers should report all cases of Zika virus disease to local and state health departments, including those suspected to have occurred by sexual transmission.

In Summary:

Non-pregnant women and all men with Zika virus exposure and symptoms consistent with Zika virus should be tested.

Non-pregnant women and all men with Zika virus exposure but without symptoms consistent with Zika virus exposure should not be tested.

Pregnant women with Zika virus exposure should be tested following Figure 1 regardless of symptom status.

Importantly, some areas within the U.S. are now considered areas of local transmission (see Travel Restrictions). As such, pregnant women who live in or travel frequently to these areas (or whose partner lives in or travels frequently to these areas) should be managed as though they have an ongoing risk for Zika virus infection; pregnant women who have traveled to these areas (or whose partner has traveled to these areas) should be managed as though they have had recent Zika virus exposure. Currently, the clinical guidance in the testing and management algorithms have not changed, even given these locally-acquired cases in the U.S.

Testing and Evaluation of Pregnant Women (Figure 1):

Zika virus testing of pregnant women should follow the algorithm in Figure 1, noting that inconclusive test results should be treated as a positive Zika virus result.

Zika virus testing is performed at the CDC Arbovirus Diagnostic Laboratory, most state health departments, and some commercial laboratories per FDA's Zika virus emergency use authorization. Currently, it is not certain that all laboratories performing rRT-PCR offer Zika IgM testing or confirmatory serologic testing such as PRNT, or may not have a process to forward specimens to another testing laboratory. Therefore, additional testing may not be done automatically, or as a “reflex”. Because lack of reflex capability leads to a potential safety risk, ACOG recommends that ob-gyns use labs that have combined rRT-PCR and IgM and PRNT testing. State health departments have combined testing and provide preventive education to pregnant women. A few commercial labs are beginning to offer combined testing. Limitations of laboratory tests used to diagnose Zika virus infection should also be discussed with pregnant women. ACOG also recommends that providers, when drawing samples, consider storing additional serum samples for further testing if needed given that further testing may not be done as a reflex; this is particularly true when drawing samples for IgM testing 2-12 weeks after exposure or symptom onset or when drawing samples for symptomatic patients who present within 2 weeks of symptom onset. ACOG encourages providers to contact their local state health department or their commercial laboratory to be aware of how their laboratory performs Zika virus testing so that providers can retain or collect additional serum specimens as needed.

The decision to implement testing of asymptomatic pregnant women with ongoing risk for Zika virus exposure should be made by local health officials based on information about levels of Zika virus transmission and laboratory capacity.

Providers should follow CDC’s information on how to best collect and submit body fluids for Zika virus testing and should indicate a patient’s pregnancy status when submitting serum samples. While the CDC has made efforts to expand the availability of testing, priority for Zika virus testing should be given to pregnant women with possible exposure.

For those patients who have a recent (0-12 weeks) or ongoing exposure, testing recommendations vary depending on time of exposure and whether or not symptoms are present. It is important to note that, regardless of symptoms, testing is not recommended unless there is a recent past or ongoing exposure.

For exposed and symptomatic pregnant women who present within two weeks after symptom onset (Figure 1 – Left Column A): Provider submits serum and urine samples for Zika rRT-PCR testing. Not all laboratories have the capacity to perform confirmatory follow up testing automatically (as a "reflex") or to forward specimens to another testing laboratory. Because of this, providers should consider storing additional samples for further testing if needed.

A positive result is confirmatory for recent Zika virus infection.

A negative result requires further Zika virus and dengue virus IgM testing according to Figure 1 – Left Column A. A positive or equivocal Zika virus or dengue virus IgM antibody test indicates a presumptive recent Zika virus or dengue virus or flavivirus infection and PRNT should be performed on the same IgM-tested sample or a subsequently collected sample to rule out false-positive results. Zika virus PRNT ≥ 10 with a dengue virus PRNT < 10 indicates a recent Zika virus infection; when both Zika virus PRNT and dengue virus PRNT are ≥ 10, this indicates a recent flavivirus infection although the specific virus cannot be identified; a Zika PRNT <10 indicates no recent evidence of Zika virus infection.

For exposed and symptomatic pregnant women who present within 2-12 weeks after symptom onset (Figure 1 – Right Column B): Provider submits serum samples for Zika virus and dengue virus IgM antibody testing. Because not all laboratories have the capacity to perform PRNT and/or rRT-PCR testing, all providers should consider storing additional serum samples for further testing if needed.

A negative result for both IgM tests indicates no recent Zika virus infection and no further testing is recommended although a prenatal ultrasound to evaluate for fetal abnormalities consistent with congenital Zika virus syndrome is recommended (Table 2).

A positive or equivocal result indicates presumptive Zika virus or flavivirus infection and the laboratory should automatically perform reflex rRT-PCR testing on the same serum sample and urine sample (if available) to determine whether Zika virus RNA is present. A positive rRT-PCR result confirms the diagnosis of recent maternal Zika virus infection. However, a negative rRT-PCR result should be followed by PRNT on the same IgM-tested sample or a subsequently collected sample. Zika virus PRNT ≥ 10 with a dengue virus PRNT < 10 indicates a recent Zika virus infection; when both Zika virus PRNT and dengue virus PRNT are ≥ 10, this indicates a recent flavivirus infection although the specific virus cannot be identified; a Zika PRNT <10 indicates no recent evidence of Zika virus infection.

For exposed and asymptomatic pregnant women NOT living in an area with active Zika virus transmission who present within two weeks after possible exposure (Figure 1 – Left Column A): Provider submits serum and urine samples for Zika rRT-PCR testing.

A positive result is confirmatory for recent Zika virus infection.

A negative result requires further Zika virus IgM testing 2-12 weeks after exposure according to Figure 1 – Left Column A. Therefore, women should return 2-12 weeks after possible Zika virus exposure for Zika virus IgM antibody testing, at which point providers should consider storing additional serum samples for further PRNT testing if needed. A positive or equivocal Zika virus IgM antibody test indicates a presumptive recent Zika virus or flavivirus infection and PRNT should be performed on the same IgM-tested sample or a subsequently collected sample to rule out false-positive results. Zika virus PRNT ≥ 10 with a dengue virus PRNT < 10 indicates a recent Zika virus infection; when both Zika virus PRNT and dengue virus PRNT are ≥ 10, this indicates a recent flavivirus infection although the specific virus cannot be identified; a Zika PRNT <10 indicates no recent evidence of Zika virus infection.

For exposed and asymptomatic pregnant women NOT living in an area with Zika virus transmission who present 2-12 weeks after possible exposure (Figure 1- Right Column B): Provider submits serum samples for Zika virus IgM antibody testing. Because not all laboratories have the capacity to perform PRNT and/or rRT-PCR testing, as noted above, all providers should consider storing additional serum samples for further testing if needed.

A negative result for Zika virus IgM antibody test indicates no recent Zika virus infection and no further testing is recommended although a prenatal ultrasound to evaluate for fetal abnormalities consistent with congenital Zika virus syndrome is recommended (Table 2). If fetal abnormalities associated with Zika virus infection are present, retesting may be considered.

A positive or equivocal result indicates presumptive Zika virus or flavivirus infection and the laboratory should automatically perform reflex rRT-PCR testing on the same serum sample and urine sample (if available) to determine whether Zika virus RNA is present. A positive rRT-PCR result confirms the diagnosis of recent maternal Zika virus infection. However, a negative rRT-PCR result should be followed by PRNT on the same IgM-tested sample or a subsequently collected sample. Zika virus PRNT ≥ 10 with a dengue virus PRNT < 10 indicates a recent Zika virus infection; when both Zika virus PRNT and dengue virus PRNT are ≥ 10, this indicates a recent flavivirus infection although the specific virus cannot be identified; a Zika PRNT <10 indicates no recent evidence of Zika virus infection.

For asymptomatic women with an ongoing risk for Zika virus transmission (first and second trimester) (Figure 1 – Right Column B): Provider submits serum sample for Zika IgM antibody testing as part of routine obstetric care during the first and again in the second trimesters.

A positive or equivocal result indicates presumptive Zika virus or flavivirus infection and the laboratory should automatically perform reflex rRT-PCR testing on the same sample to determine whether Zika virus RNA is present. A positive rRT-PCR result confirms the diagnosis of recent maternal Zika virus infection. However, a negative rRT-PCR result should be followed by PRNT on the same IgM-tested sample or a subsequently collected sample. Zika virus PRNT ≥ 10 with a dengue virus PRNT < 10 indicates a recent Zika virus infection; when both Zika virus PRNT and dengue virus PRNT are ≥ 10, this indicates a recent flavivirus infection although the specific virus cannot be identified; a Zika PRNT <10 indicates no recent evidence of Zika virus infection.

The implications of Zika infection occurring in the third trimester are still being investigated. At this time, data are not available to make recommendations regarding repeat testing in the third trimester. However, as new data emerges, recommendations regarding repeat testing for pregnant women with ongoing risk for Zika virus transmission will be updated.

For symptomatic and asymptomatic pregnant women who seek care >12 weeks after symptom onset or possible Zika virus exposure: Providers may consider IgM antibody testing. If fetal abnormalities associated with Zika virus infection are present, rRT-PCR testing should also be performed on maternal serum and urine. However, a negative IgM antibody test or rRT-PCR result >12 weeks after symptom onset or possible exposure does not rule out recent Zika virus infection because IgM antibody and viral RNA levels decline over time. Given the limitations of testing beyond 12 weeks after symptom onset or possible exposure, serial fetal ultrasounds should be considered.

a Because lack of reflex capability leads to a potential safety risk, ACOG recommends that ob-gyns use labs that have combined rRT-PCR and IgM and PRNT testing. State health departments have combined testing and provide preventive education to pregnant women. A few commercial labs are beginning to offer combined testing. Limitations of laboratory tests used to diagnose Zika virus infection should also be discussed with pregnant women.

e A negative result for both IgM tests indicates no recent Zika virus infection and no further testing is recommended although a prenatal ultrasound to evaluate for fetal abnormalities consistent with congenital Zika virus syndrome is recommended.

f Testing for asymptomatic, non-pregnant sexual partners (with or without potential Zika exposure) of pregnant women is not currently supported by the CDC guidelines.

h A negative IgM antibody test or rRT-PCR result >12 weeks after symptom onset or possible exposure does not rule out recent Zika virus infection because IgM antibody and viral RNA levels decline over time. Given the limitations of testing beyond 12 weeks after symptom onset or possible exposure, serial fetal ultrasounds should be considered.

I A prenatal ultrasound to evaluate for fetal abnormalities consistent with congenital Zika virus syndrome is recommended for all pregnant women tested for Zika, regardless of laboratory findings. Repeat imaging should be considered if Zika testing suggests infection. Limited exposure in the absence of a positive serologic test does not warrant additional ultrasound testing.

j For asymptomatic women with ongoing exposure, IgM testing is recommended in the first trimester and again in the second trimester.

kIf the same sample cannot be used for reflex RT-PCR, then a sample should be obtained as soon as possible given that RNA levels decline over time

The many uncertainties about Zika virus biology highlight the challenges of managing and counseling about exposures and infection in pregnancy. Referral to a maternal–fetal medicine or infectious disease specialist with expertise in pregnancy management is recommended and may be useful particularly for those pregnancies with demonstrated maternal infection or concerning fetal findings.

Given that serology test results can be difficult to interpret, particularly in persons who were previously infected with or vaccinated against flaviviruses, and because of the adverse outcomes caused by Zika virus infection during pregnancy are not fully described, pregnant women with laboratory evidence of recent flavivirus infection are considered to have possible Zika virus infection and should be monitored frequently.

Pregnant women with confirmed or possible Zika virus infection and women with presumptive recent Zika virus or flavivirus infection should be managed in accordance with Table 2. Persistent detection of Zika virus RNA in serum has been reported during pregnancy. While the clinical implications of prolonged detection of Zika virus RNA in serum are not known, repeat rRT-PCR testing has been performed in some cases. Currently, there is insufficient information to make recommendations regarding repeat rRT-PCT testing in pregnant women. As new data emerge, recommendations regarding repeat rRT-PCR testing in pregnant women will be updated.

It is important that maternal Zika virus exposure and testing information be available and communicated to the pediatric provider so that appropriate infant testing and management can be implemented in accordance with existing guidance. It is particularly important that this information be conveyed while neonates are hospitalized after birth to allow for collection of infant specimens within 2 days of birth.

ǂHealth care providers should discuss risks and benefits of amniocentesis with their patients. It is not known how sensitive or specific rRT-PCR testing of amniotic fluid is for congenital Zika virus infection, whether a positive result is predictive of a subsequent fetal abnormality, and if it is predictive, what proportion of infants born after infection will have abnormalities.

§ For example, positive or equivocal Zika virus or dengue virus IgM antibody test result that needs to be confirmed by PRNT.

││rRT-PCR or PRNT should be performed for positive or equivocal IgM results as indicated. PRNT results that indicate recent flavivirus infection should be interpreted in the context of the currently circulating flaviviruses. Refer to the laboratory guidance for updated testing recommendations (http://www.cdc.gov/zika/laboratories/lab-guidance.html). Because of the overlap of symptoms and areas where other viral illnesses are endemic, evaluate for possible dengue or chikungunya virus infection.

Ultrasound examinations should be used to assess fetal anatomy, particularly neuroanatomy, and to monitor growth. They should focus on development of findings such as intracranial calcifications, microcephaly, ventriculomegaly, arthrogryposis; abnormalities of the corpus callosum, cerebrum, cerebellum, and eyes; and other brain abnormalities, as those abnormalities have been most frequently reported in affected pregnancies. The International Society of Ultrasound in Obstetrics and Gynecology offers a tutorial to help providers learn more on how to improve their Congenital Zika Virus Syndrome diagnostic capabilities.

One reassuring ultrasound, particularly if obtained close to the time of infection, may not preclude later manifestations, and cases with delayed findings have been reported. Repeat imaging should be considered if Zika testing suggests infection. If maternal testing does not suggest infection and exposure is not ongoing, serial ultrasounds are unlikely to be needed.

When imaging raises suspicion for fetal infection, amniocentesis for Zika virus testing of amniotic fluid may be considered on a case by case basis. While it is assumed that assay performance on amniotic fluid is similar to that with maternal serum, this is not certain. Nor is it known how long after a pregnant woman becomes infected she can transmit the virus to the fetus, for what duration amniotic fluid will be rRT-PCR positive, or what the ability of the test is to determine the presence of fetal injury.

Counseling During Pregnancy:

Obstetrician-gynecologists should be prepared to counsel pregnant women exposed to Zika or at risk of exposure about the virus and reproductive options. Like all pregnancies, Zika-infected pregnant women should have full access to the most complete range of reproductive options, including termination.

Counseling related to Zika virus should be individualized and could include the following:

There is a demonstrated causation between Zika virus infection during pregnancy and adverse pregnancy outcomes. However, there are still uncertainties regarding the rate of vertical transmission and the rate with which infected fetuses manifest complications such as microcephaly, demise, or congenital Zika syndrome.

Zika virus testing is complicated and can result in false-positives and false-negatives, making it difficult to exclude infection. Limitations of laboratory tests used to diagnose Zika virus infection should also be discussed with pregnant women.

One reassuring ultrasound, particularly if obtained close to the time of infection, may not preclude later manifestations, and cases with delayed findings have been reported. If maternal testing does not suggest infection and exposure is not ongoing, serial ultrasounds are unlikely to be needed.

Congenital Zika syndrome — a recently recognized pattern of congenital anomalies associated with Zika virus infection during pregnancy that includes microcephaly, intracranial calcifications or other brain anomalies, or eye anomalies, among others — may present well after birth.

Breastfeeding:

Although the presence of Zika virus in breast milk has been reported, there are no reports of infants getting Zika virus through breastfeeding. Infection through oral intake is not known. The benefits of breastfeeding likely outweigh the potential neonatal risks. Therefore, the recommendation is that women should continue to breastfeed, even in areas where Zika virus is found.

Reporting:

Obstetrician–gynecologists will need to report pregnant women with any laboratory evidence of Zika virus infection (positive or inconclusive test results) as well as any adverse outcomes to the state health department (see U.S. Zika Pregnancy Registry for details).

For women with presumptive Zika virus or flavivirus infection, submitting placental and umbilical cord specimens for live births or submitting fetal tissue specimens for fetal loss should be considered for IHC staining and rRT-PCR testing (see Table 3).

For women with possible exposure but for whom maternal testing did not occur, or for whom testing was performed more than 12 weeks after exposure, maternal Zika virus testing should be performed and placental testing may also be considered. For those presenting outside the recommended testing window, providers may consider IgM antibody testing. If fetal abnormalities associated with Zika virus infection are present, rRT-PCR testing should also be performed on maternal serum and urine.

Infant without findings consistent with congenital Zika syndrome: infant testing should be considered. **, If maternal IgM testing is performed outside the recommended testing window (> 12 weeks from symptom onset or exposure), negative maternal testing may not rule out maternal infection. In this circumstance infant testing may be more informative than maternal testing.

Infant without findings consistent with congenital Zika syndrome: infant testing should be considered.** Negative maternal testing may not rule out maternal infection. In this circumstance infant testing may be more informative than maternal testing.

ǂ For example, positive or equivocal Zika virus or dengue virus IgM antibody test result that needs to be confirmed by PRNT.

§ Mothers should be tested by rRT-PCR within 2 weeks of exposure or symptom onset, or by IgM within 2–12 weeks of exposure or symptom onset.

││For those presenting outside the recommended testing window, providers may consider IgM antibody testing. Because of the decline in IgM antibody titers and viral RNA levels over time, negative maternal testing 12 weeks after exposure does not rule out maternal infection.

If fetal abnormalities associated with Zika virus infection are present, rRT-PCR testing should also be performed on maternal serum and urine.

¶ If cerebrospinal fluid (CSF) is obtained for other studies.

†† If infant testing is planned, it is reasonable for providers not to wait for results of any maternal/placenta testing to obtainthe infant specimens within the first 2 days of life, if possible.

Neonatal Outcomes and Evaluation

Reporting and the U.S. Zika Pregnancy Registry

(Updated: August 3, 2016)

As part of the response to the Zika outbreak, the CDC, in collaboration with state, tribal, local, and territorial health departments, established a pregnancy registry for comprehensive monitoring of pregnancy and infant outcomes following possible Zika virus infection. The registry is an active surveillance system of pregnant women with laboratory evidence of possible or confirmed Zika virus infection in the 50 U.S. states and DC, and in the U.S. territories. Detailed information about the registry includes weekly reporting of the number of pregnant women followed in the registry.

Obstetrician–gynecologists will need to report pregnant women with any laboratory evidence of Zika virus infection (positive or inconclusive test results) as well as any adverse outcomes to the state health department. They can expect follow up from health officials during the pregnancy and at the time of expected birth to collect surveillance data. CDC registry staff will work with state health departments to assist with collection of information. Ob-gyns can also contact the CDC pregnancy hotline (call 770-488-7100 or email ZikaPregnancy@cdc.gov) to discuss women with laboratory evidence of Zika virus infection. If they contact CDC for clinical consultation, registry staff will ensure that state, tribal, local, or territorial health departments are notified.

ACOG strongly encourages all members to support the registry by reporting eligible cases and by designating staff who can assist in the completion of pregnancy data collection forms and who will be responsible for reporting pregnant women with Zika virus to their health department.

Understanding the range of health effects linked with Zika infection during pregnancy, as well as which pregnancies may be at risk for poor outcomes is essential. The data collected through these registries will be used to update recommendations for diagnostic testing, prenatal care and monitoring, and counseling of pregnant women and families affected by Zika virus. Information about the number of pregnant women affected will also assist in planning for services for these women, infants and families. Each new data point collected through these surveillance systems contributes to what we know about Zika virus, which will improve the care we provide to patients affected by the virus.

Infection Control Considerations

(Updated: August 3, 2016)

Zika virus RNA has been detected in many body fluids, including blood, urine, saliva, and amniotic fluid and minimizing exposures to body fluids is important. CDC, ACOG and SMFM recommend Standard Precautions in health care settings to protect obstetrician–gynecologists and other health care providers and patients from infection with Zika virus as well as from blood-borne pathogens. This emphasizes what should already be usual and expected practice. Adherence to Standard Precautions, the basic infection prevention measures that apply to patient care in all heath care settings, is necessary to protect health care providers and patients in labor and delivery settings from transmission of Zika virus, as well as blood-borne pathogens, such as human immunodeficiency virus and hepatitis C. The appropriate use of personal protective equipment is important for all health care providers to minimize the risk of transmission of infectious pathogens through exposure to blood and body fluids. There is no evidence that contact precautions or respiratory isolation of Zika virus-infected patients is warranted.

In light of the recent case of Zika in Utah, CDC and ACOG have reviewed infection control considerations for health care providers and continue to recommend Standard Precautions. However, the CDC and ACOG continue to monitor the topic and any new or additional information will be posted as it becomes available.

Zika and Blood Transfusion

(Updated: September 14, 2016)

To date, there have been no confirmed blood transfusion-transmission cases in the US, although there have been suspected cases of Zika transmission through blood transfusion in Brazil. Blood screening via questionnaire is performed throughout the U.S. However, because there is a strong possibility that Zika virus can be spread through blood transfusions, the FDA recommends that U.S. states and territories screen individual units of donated Whole Blood and blood components with a blood screening test authorized for use by the FDA under an investigational new drug application, or a licensed test when available. Alternatively, an FDA-approved pathogen-reduction device may be used for plasma and certain platelet products.

American College of Obstetricians and Gynecologist. Available at: http://www.acog.org. Retrieved October 14, 2016.

American College of Obstetricians and Gynecologists. Immunization for women. Washington, DC: American College of Obstetricians and Gynecologists; 2016. Available at: http://www.immunizationforwomen.org/. Retrieved October 14, 2016.

American College of Obstetricians and Gynecologists. ACOG Zika virus resource summary for ob-gyns and health care providers. Washington, DC: American College of Obstetricians and Gynecologists; 2016. Available at: http://www.acog.org/zika. Retrieved October 14, 2016.

Centers for Disease Control and Prevention. CDC guidance for travel and testing of pregnant women and women of reproductive age for Zika virus infection related to the investigation for local mosquito-borne Zika virus transmission in Miami-Dade and Broward counties, Florida. Atlanta (GA): CDC; 2016. Available at: https://emergency.cdc.gov/han/han00393.asp. Retrieved August 2, 2016.

Centers for Disease Control and Prevention. Preconception counseling: for women and men living in areas with ongoing spread of Zika virus who are interested in conceiving. Atlanta (GA): CDC; 2016. Available at: https://www.cdc.gov/zika/pdfs/preconception-counseling.pdf. Retrieved March 30, 2016.

Centers for Disease Control and Prevention. Recognizing, managing, and reporting Zika virus infections in travelers returning from Central America, South America, the Caribbean, and Mexico. Atlanta (GA): CDC; 2016. Available at: http://emergency.cdc.gov/han/han00385.asp. Retrieved March 30, 2016.

This Practice Advisory was developed by the American College of Obstetricians and Gynecologists and the Society for Maternal–Fetal Medicine in collaboration with Laura E. Riley, MD, Jeffrey L. Ecker, MD, and R. Phillips Heine, MD.

A Practice Advisory is issued when information on an emergent clinical issue (eg, clinical study, scientific report, draft regulation) is released that requires an immediate or rapid response, particularly if it is anticipated that it will generate a multitude of inquiries. A Practice Advisory is a brief, focused statement issued within 24–48 hours of the release of this evolving information and constitutes ACOG clinical guidance. A Practice Advisory is issued only online for Fellows but may also be used by patients and the media. Practice Advisories are reviewed periodically for reaffirmation, revision, withdrawal, or incorporation into other ACOG guidelines.
This document reflects emerging clinical and scientific advances as of the date issued and is subject to change. The information should not be construed as dictating an exclusive course of treatment or procedure to be followed.

The American College of Obstetricians and Gynecologists (The College), a 501(c)(3) organization, is the nation's leading group of physicians providing health care for women. As a private, voluntary, nonprofit membership organization of more than 57,000 members, The College strongly advocates for quality health care for women, maintains the highest standards of clinical practice and continuing education of its members, promotes patient education, and increases awareness among its members and the public of the changing issues facing women’s health care. The American Congress of Obstetricians and Gynecologists (ACOG), a 501(c)(6) organization, is its companion organization. www.acog.org

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